Alkynes – unsaturated hydrocarbons (CnH2n-2):

Alk yne s – unsaturated hydrocarbons (C n H 2n-2 ) physical properties: boiling points slightly higher than that of alkanes and alkenes specific gravity higher in comparision to alkenes the triple bond = 1  and 2 bonds it is shorter than the double bond the reactivity of the triple bond is similar to that of the double bond of alkenes (addition reactions) ethyne (= acetylene ): all four atoms in a stright line